In a New Radio (NR) communications system, a CSI-RS resource set includes one or more channel state information-reference signal (CSI-RS) resources. Each CSI-RS resource corresponds to a maximum of 32 antenna ports (AP). When a CSI-RS resource is used for beam measurement and reporting, each CSI-RS resource corresponds to two antenna ports. A timeslot offset (slot offset) is an offset between a timeslot in which a base station sends a CSI-RS trigger indication and a timeslot in which a CSI-RS is actually sent. In a current solution, a base station may send CSI-RSs aperiodically. In this case, a timeslot offset of a CSI-RS is 0 by default. In other words, the base station can send the CSI-RS only in a timeslot in which a CSI-RS trigger indication is sent (triggering in current timeslot and sending also in current timeslot).
The current CSI-RS sending manner causes low system efficiency. For example, in a scenario in which a CSI-RS is used for beam measurement and reporting, because a timeslot includes a limited quantity of orthogonal frequency division multiplexing (OFDM) symbols that can be used to send CSI-RSs which carry analog beams, when a relatively large quantity of beams need to be scanned, a plurality of CSI-RS resource sets are configured to send respective CSI-RSs in different timeslots. In this case, frequent triggering and frequent reporting are required. This configuration method wastes uplink resources, and is limited by a capability of a terminal device, resulting in low system efficiency.